Remove all resolutions guessing

[tmcw]

Via this comment:

    // ok we want resolutions, here's our strategy:
    //
    // 1. if resolutions are defined in the layer config, use them
    // 2. else, if scales are defined in the layer config then derive
    //    resolutions from these scales
    // 3. else, attempt to calculate resolutions from maxResolution,
    //    minResolution, numZoomLevels, maxZoomLevel set in the
    //    layer config
    // 4. if we still don't have resolutions, and if resolutions
    //    are defined in the same, use them
    // 5. else, if scales are defined in the map then derive
    //    resolutions from these scales
    // 6. else, attempt to calculate resolutions from maxResolution,
    //    minResolution, numZoomLevels, maxZoomLevel set in the
    //    map
    // 7. hope for the best!

This is the cause of 95% of help requests I see around OpenLayers. There should be two modes: calculate based on zoom levels, and give a specific set of resolutions. This guessing is just too much cognitive overhead and magic to be anywhere near predictable for implementations.

[elemoine]

Yeah, I wrote these lines when I reworked initResolutions. The rewrite was under b/w compatibility constraints obviously.